fix stdout assumptions

stdout, just like stderr, may be None which would cause a heap of problems
see 02733bc

mesonbuild/mesonmain.py

@@ -217,7 +217,7 @@ def run_script_command(script_name, script_args):
         return 1
 
 def ensure_stdout_accepts_unicode():
-    if sys.stdout.encoding and not sys.stdout.encoding.upper().startswith('UTF-'):
+    if sys.stdout is not None and sys.stdout.encoding and not sys.stdout.encoding.upper().startswith('UTF-'):
         sys.stdout.reconfigure(errors='surrogateescape')
 
 def set_meson_command(mainfile):

mesonbuild/mlog.py

@@ -49,6 +49,9 @@ def _windows_ansi() -> bool:
     return bool(kernel.SetConsoleMode(stdout, mode.value | 0x4) or os.environ.get('ANSICON'))
 
 def colorize_console() -> bool:
+    if sys.stdout is None:
+        return False
+
     _colorize_console: bool = getattr(sys.stdout, 'colorize_console', None)
     if _colorize_console is not None:
         return _colorize_console

mesonbuild/utils/universal.py

@@ -1512,7 +1512,7 @@ def Popen_safe(args: T.List[str], write: T.Optional[str] = None,
         stdin = subprocess.PIPE
 
     try:
-        if not sys.stdout.encoding or encoding.upper() != 'UTF-8':
+        if (sys.stdout is not None and not sys.stdout.encoding) or encoding.upper() != 'UTF-8':
             p, o, e = Popen_safe_legacy(args, write=write, stdin=stdin, stdout=stdout, stderr=stderr, **kwargs)
         else:
             p = subprocess.Popen(args, universal_newlines=True, encoding=encoding, close_fds=False,
@@ -1542,7 +1542,7 @@ def Popen_safe_legacy(args: T.List[str], write: T.Optional[str] = None,
         input_ = write.encode('utf-8')
     o, e = p.communicate(input_)
     if o is not None:
-        if sys.stdout.encoding is not None:
+        if sys.stdout is not None and sys.stdout.encoding is not None:
             o = o.decode(encoding=sys.stdout.encoding, errors='replace').replace('\r\n', '\n')
         else:
             o = o.decode(errors='replace').replace('\r\n', '\n')